You'll see the title bar quite often so it's important to understand the information displayed there. In the image below the title bar is outlined in red.

The left most section of the title bar is the date the feed article was published.

Clicking the star icon is how you save articles. It comes in handy if you don't have time to read the article when you first see it, but want to read it later. You might also refer to this feature as Bookmarks or Favorites.

Mark Read simply marks the article read so it won't show up next time you load a page that's set to only show unread articles.

The last part of the title bar, in this case Slashdot, is the feed title. The feed title doesn't show up when viewing a specific feed as it's implied in this case, but it will be there in the Interesting, All, and Popular views.